However, users that bought their music on iTunes before Apple abandoned DRM some two years ago better get ready for an unexpected surprise: Files originally bought with Apple’s Fairplay copy protection are also once again downloaded with DRM.

Apple still charges users $0.30 per track to get rid of DRM.

A number of users complained about this strange behavior on Twitter and on the web, with one stating that this would bring back “bad memories.” We were able to confirm it by re-downloading a DRMed track as well. Apple introduced the ability to “upgrade” copy protected tracks to DRM-free AACs by paying $0.30 per song in early 2009. The so-called upgrade to iTunes Plus is still available, so it might make economic sense for the company to not offer free upgrades as part of the new ability to download additional copies of previously purchased songs.

However, the fact that iTunes still serves up DRM to users who were honest enough to pay for their music may add fuel to recent criticism that Apple’s iCloud offering rewards piracy. Beginning this fall, customers will be able to synchronize their entire music library with iCloud without uploading a single song to Apple’s servers as part of the iTunes Music Match subscription. iCloud will instead match songs by title and audio fingerprint, allowing users to download higher-quality copies of songs even for those 128 kbps files they originally downloaded from LimeWire back in the day. Music Match will cost users $25 per year.

The good news is that iCloud’s Music Match will likely also work for DRMed iTunes purchases (Apple PR didn’t respond in time to requests for comment), meaning that paying subscribers will be able to free their existing iTunes libraries from DRM by paying $25 per year instead of $0.30 per track.

Until then, Apple’s practice of serving up DRMed downloads to paying customers more than two years after the company announced with big fanfares that it would abandon DRM serves as an important reminder: Once businesses and consumers buy into a copy protection scheme, they’re gonna have a hard time getting rid of it.